After four dry days, showers are returning to Perth and are likely each day through to the end of next week, bringing 30 to 50 millimetres of rain.

The area from Mandurah to Margaret River should be the wettest with more than 50mm for some.

The wettest days are likely to be today, Saturday and Monday as three cold fronts link up with bands of cloud from the Indian Ocean.

These days are also likely to be the windiest with potential severe gusts of 90kmh or stronger in coastal parts, south of about Perth. Winds of this strength can bring down trees. Gusts in excess of 100kmh cannot be ruled out.

July is traditionally the wettest month of the year for southwest Western Australia and this coming wet spell will take most of the region to about two-thirds of the monthly average. So far, less than half the monthly average rainfall has fallen.

Perth has had 52mm, compared to the average of 149mm.

With this rain to come, this July is still unlikely to be wetter than last year when 179mm fell.

Winds travelling at more than 100km/h tore through the city overnight, ripping the roof off a granny flat in Doubleview, collapsing a ceiling in Joondalup and blowing in the windows of a house in City Beach.

More than 17,000 are believed to be without power because of the storm, mostly in the Perth hills.

State and Emergency Services (SES) have recorded 70 calls for help since 7am, with a total of 125 incidents logged since 6pm last night and 240 properties impacted.

Damage has been reported in coastal suburbs from Two Rocks to Rockingham and all SES units in the metropolitan area have been activated with volunteers in Northam called in for backup.

A series of cold fronts have been lashing the city since Friday, with Rottnest, Ocean Reef, Mandurah and Bickley some of the worst hit areas.

Ocean Reef recorded a wind gust of 107km/h and gusts of 115km/h were recorded at Rottnest, where ferry services have been cancelled.

The ports of Fremantle and Kwinana ports have suspended operations until midday.

Across the state, Cape Naturalist and Cape Leeuwin recorded wind gusts of up to 109km/h. There have been reports of fallen trees and minor damage to homes in Bunbury, Busselton and Capel.

The WA Bureau of Meteorology says it is the wettest day of the year.

Flights from Perth’s international terminal are running half an hour behind schedule, and Main Roads are urging motorists to slow down and take care in the inclement weather.

Near the city, waves from the Swan River were lapping around peak hour traffic on the Kwinana Freeway this morning, while Riverside Drive and parts of Beaufort St have isolated flooding.

Traffic lights are out on the intersection of Great Eastern Highway and Stoneville Rd in Mundaring and at the junction of Kalamunda Rd and Gooseberry Hill Rd.

WA Bureau of Meteorology climate information officer John Relf says 23.2mm of rain has fallen overnight taking Perth much closer to the 177mm average with 147.8mm of rain recorded this month.

“We have exceeded last year’s June rainfall of 142mm,” he said.

Heavy rain has been reported from Collie to Walpole.

WA Water Corporation spokeswoman Clare Lugar says dams should have now started benefiting from the all rainfall.

“Up until Friday the streams hadn’t started to flow,” Ms Lugar said. “But we are expecting it to have begun flowing over the weekend.”

The wild weather is expected to ease up later tonight with fine weather forecast by Thursday.

The latest in a series of destructive cold fronts slammed into WA overnight, causing destructive winds, rain and hail storms.

The Bureau of Meteorology issued a severe weather warning at 6.45am, following similar warnings issued throughout the weekend.

Waves from the Swan River are washing onto the Kwinana Freeway north of Canning Highway citybound. There is also flooding on Beaufort Street in Inglewood heading into the city and on Riverside Drive.

Traffic lights are blacked out at the Great Eastern Highway and Bolton Road intersection in Burswood.

The front is the most severe of a series that have descended on WA over the past few days.

A wind gust of 115kmh was recorded at Rottnest Island about 6am today, and the Bureau is warning people to expect winds up to 100kmh with potentially damaging gusts reaching 125kmh this morning.

Alex Krisman from WeatherZone said Cape Naturaliste (109kmh) and Cape Leeuwin (104kmh) also recorded heavy gusts of wind – which coincided with a line of lightning flashes- at the same time as Rottnest Island.

Winds at Perth Airport hit 83kmh while the Perth metropolitan area clocked speeds up to 72kmh at 5.50am.

Rainfall was heavy, particularly across the south west. So far, Bridgetown has had 32mm from 9am yesterday morning.

Thunderstorms and heavy showers are forecast for today, particularly over the Lower West, South-West and South Coastal districts.

Abnormally high tides are set to cause flooding in low-lying coastal areas.

A gale warning has been issued from Kalbarri right through to the South Australian border.

Surfers are being warned to brace for heavy conditions, which are likely to cause significant beach erosion.

The State Emergency Service has warned people to secure loose objects, move vehicles under cover and stay inside away from windows.

People caught outdoors should find shelter away from trees, powerlines, storm water drains and streams. Boat owners should make sure their boats are securely moored.

Gale force winds tipped to hit Perth this weekend have forced two ferry operators to cancel all trips to Rottnest Island.

The popular Rottnest Express confirmed it has cancelled all bookings from Friday to Sunday inclusive while Oceanic Cruises will not operate on Saturday or Sunday.

The third company which operates ferry trips to the island, Rottnest Fast Ferries, was already closed until July 3 for its regular winter break.

A Rottnest Express spokesman confirmed there had been “a few” bookings and all passengers would be issued refunds, while Oceanic Cruises did not have any bookings for this weekend.

Bureau of Meteorology public weather services manager Neil Bennett said waters from Yanchep to Mandurah and offshore to Rottnest Island could expect winds reaching between 30 to 40 knots on Friday and Saturday.

Mr Bennett said it was likely the Bureau would issue at least a strong wind warning but likely a gale force wind warning for the area.

Weatherzone meteorologists are forecasting wetter, windier and colder weather for most of the southern half of the state starting on Wednesday.

Weatherzone Head Meteorologist Matthew Pearce said the strength of the cold front would likely result in 20 to 30mm of rain along the coast and exposed areas stretching as far north as Geraldton and at least 5mm everywhere else.

Currently the weather is fine and sunny at 16 degrees with an expected top today of 25 degrees which will last until Sunday.

Some light showers should set in ahead of the cold front early next week.